Masturbation is when people rub their own genitals (the penis in males or the the vagina in females) because they like the way it feels. Lots of people have heard all sorts of crazy stuff about masturbation — that it can cause diseases, interfere with growth, cause mental problems, lead to blindness, or stop a person from having children.

When does a penis stop growing? Your penis stops growing when you finish puberty. Exactly when that happens, though, varies from person to person. Everyone develops at a different pace. You may take longer than your friends or less time than them to finish puberty. But by 16, your body and its parts should be close to your adult size.